Using Consequence Modeling to Help Make Emergency Decisions Della Wong / Nova Chemicals & Robert B. Gerow / SAFER-ERMC CSChE 2002 Conference October 20-23, 23, 2002 Vancouver B.C.
If auto safety was like some emergency response & crisis management programs, we'd be buying seat belts and air bags while our cars were skidding towards a wall at high speed.
If it happened today How would the impact zone be estimated? What would be a suitable staging area for the response team? Will the release reach populated areas? How much time do we have? How can we identify those affected? What concentrations will they be exposed to? How would you decide between a Shelter-In- Place vs Evacuation recommendation?
EOC ORGANIZATION Emergency Operation Centre Management Group UNIT LEADER Logistics Coordinator EOC MANAGER Public Information Coordinator Planning Coordinator Resources: Environment / Hygiene EOC Coordinator Emergency Coordinator Building / Headcount Coordinator General Site Population EOC Administrator IT Field Response Group Engineering Unit Leadership Representative Unit Operations Leader (UOL) Operator Maintenance NOVA INCIDENT COMMANDER Emergency Resource Leader Attack Leader Health Services Emergency Response Teams Mutual Aid
EOC FUNCTION Direct support to the Field Command Structure Support to and management of unaffected areas Site communication & evacuation management Long term incident response planning Manage outside influences Media, public & investor relations, special interest groups External communications Corporate, government Post incident recovery operations
ENGINEERING FUNCTION Directs Capital Engineering group and construction technical support staff Provides technical support (drawings, tech data, consequence modeling) Maintain P&IDS and list of resources from within the engineering group Regulatory reporting and interfacing Environmental input monitoring Employee/public exposure monitoring (Ind. Hygiene) Risk assessment services Assists the post-emergency recovery stage Maintains a log of calls and activities relevant to this role
SUPPORTING Industrial Rescue Natural Disasters Workplace Violence Flammable Spill / Release Toxic Vapour / Liquid Release
EXAMPLES Vessel ruptures Explosions Process unit fires requiring shutdown or isolation requiring activation of deluge or Halon system dumps Tank truck / rail car fires and releases
EXAMPLES Fire releasing significant quantities of toxic byproducts from combustion that requires monitoring Large electrical or substation fires Large piping or pipeline releases and fires Any fire or release involving casualties
ASSESSING RISK Location Proximity of residents & public Topography Weather Material(s) / containers involved Hazards present Toxic Flammable Environmental
ASSESSING RISK Scope of impact Numbers potentially affected contact information Time release reaches offsite Shelter in place vs evacuation Staging areas Road closures
Tools: Lookup Tables Software
GUIDEBOOK
LOOKUP TABLES: CHEMICAL NAME & CAS # PHYSICAL STATE AT 20 DEG C, 1 ATM SCENARIO ACCIDENT OUTCOMES & RESULTING EFFECT DISTANCE (m) (leak size assumes 30 minute release) ACETONE 67-64-1 Liquid, MW= 58.09 BP=56C, Flammable, Toxic fumes Tank with 1 m head Padded Liquid Horizontal leak 1 m above grade 50,000 kg with 68 mm leak pool diam.. = 44 heat flux = 85 toxic cloud = 19 explosion o/p= 124 20,000 kg with 43 mm leak pool diam. = 40 heat flux = 80 toxic cloud = 14 explosion o/p = 94
SOFTWARE: Aloha Charm Effects PHAST SAFER TRACE, Real Time & STAR
Toxic Gas Sensors Detailed Reports Release Scenario Maps Meteorology Impact on Maps Fixed Weather Stations Or Internet Weather Source Input Output Email, Phone Notification Topography Hazard Levels Chem & Phys Properties Receptors Corporate Network
THE INCIDENT Truck / train collision derailment - fire 50 kilometers east of a major city 14 cars derailed in yard 4 liquid aromatic hydrocarbons & 10 with polyethylene resin Two technical advisors onsite
THE INCIDENT
Typical Values for Thermal Radiation Watt m -2 37500 12500 9500 4000 Observed Effect Sufficient to cause damage to process equipment. Minimum energy required to ignite wood at indefinitely long exposures Minimum energy required for piloted ignition of wood, melting of plastic tubing Pain threshold reached after 8 seconds; second degree burns after 20 seconds Sufficient to cause pain to personnel if unable to reach cover within 20 seconds; however, blistering of the skin (second degree burns) is likely; 0% fatality 1600 Will cause no discomfort for long exposure Effects of Thermal Radiation [CCPS 1994]
Typical Values for Overpressure Structural Element Failure Side-on Overpressure (bar) Side-on Overpressure (psi) Glass windows Usually shattering, occasional frame failure 0.03-0.07 0.5-1 Corrugated asbestos siding Shattering 0.07-0.14 1-2 Wood siding panels standard house construction Concrete or cinder-block wall panels 8 or 12 inch thick (not reinforced) Failure, usually at main connections, allowing a whole panel to be blown- in 0.07-0.14 1-2 Shattering of wall 0.14-0.20 2-3 Self-framing steel panel building Collapse 0.20-0.28 3-4 Oil storage tank Rupture 0.20-0.28 3-4 Wooden utility poles Snapping failure 0.34 5 Loaded rail cars Overturned 0.48 7 Brick wall panel 8 or 12 inch thick (not reinforced) Shearing, flexible failure 0.55 7-8 Conditions of Failure of Side-on Overpressure-Sensitive Elements [CCPS 1994]
REPORTS Scenario Meteorology Downwind Distance Receptor Dosage Toxicity Infiltration Chemical Properties Isopleth Limits
Summary Tools can Be used for training & education Guide improved emergency response planning Help develop operational approaches for reducing hazards Demonstrate how inventory, release rate & elevation, topography, wind speed & stability can affect downwind concentrations, arrival times,etc.
ISSUES TO CONSIDER Track and Predict the Impact of Fires & Explosions Concentrations of Gases Weather Topography Population Exposure Relative to Time
ISSUES TO CONSIDER Established entity Sound operating platform Extensive field testing and experience Subject matter expertise Meets government / industry guidelines User support & recognition Ease of use Customizable - turn key set up & integration Regular updates / upgrades 24 hour expert assistance